Biomedical Engineering Reference
In-Depth Information
Fig. 6.1 The iCub platform: panel (a) a picture of the latest realization of the iCub; panel (b)
approximate dimensions height
width; and panel (c) the kinematic structure of the major joints
Cable drives were used almost everywhere on the iCub. Most joints have
relocated, motors as, for example, in the hand, shoulder (but the first joint),
elbow, waist and legs (apart from two joints). Cable drives are efficient and almost
mandatory in order to optimize the motor locations and the overall “shape” of the
robot. All joints in the hand are cable driven. The hand of the iCub has 20 joints
which are moved by nine motors: this implies that some of the fingers are under-
actuated and their movement is obtained by means of the cable couplings. Similar
to the human body, most of the hand actuation is in the forearm subsection. The
head is another particular component of the iCub enabling independent vergence
movements supported by a three DoFs neck for a total of six DoFs.
By design we decided to only use “passive sensors” and in particular cameras,
microphones, gyroscopes and accelerometers, force/torque (FTS), and tactile sen-
sors as well as the traditional motor encoders. Of special relevance is the sensorized
skin which is not easily found in other platforms as well as the force/torque sensors
that are used for force/impedance control (see later). No active sensing is provided
as, for example, lasers, structured light projectors, and so forth.
The iCub mounts custom-designed electronics which consists of programmable
controller cards, amplifiers, DACs, and digital I/O cards. This ecosystem of micro-
controller cards relies on multiple CAN bus lines (up to 10) for communication and
synchronization and then connects with a cluster of external machines via a Gbit/s
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